Table 3

Differences within the patient groups with mild or severe disease in disease activity score, levels of pro-MMP-3, -8, and -9, and activated MMP levels at baseline, one and two years

Group with mild disease (n=59)p ValueGroup with severe disease (n=50)p Value
For detailed analysis of the MMPs during the study follow up, the study group was divided into two subgroups according to progression of the JDS. Patients who had JDS progression lower than or equal to the median JDS progression of the whole study group comprised the group with mild disease, whereas patients with JDS progression greater than the median of the whole study group were included in the group with severe disease. Data shown are median (25th–75th centiles).
DAS, disease activity score; (pro)-MMP, (pro)-matrix metalloproteinase; MMP/α2M, MMP/α2 macroglobulin complexes.
p Values show the significance of the changes in each group between baseline and year 2 (linear mixed model).
JDS
    Baseline0 (0–0)2 (0–11)
    Year 10 (0–3)<0.00118 (13–41)<0.001
    Year 22 (0–6)26 (17–52)
DAS
    Baseline3.2 (2.6–4.0)3.8 (3.1–4.6)
    Year 12.7 (1.3–3.5)<0.0013.4 (2.6–4.2)<0.001
    Year 21.6 (1.1–3.0)3.0 (1.9–3.4)
Pro-MMP-3 (ng/ml)
    Baseline17 (9–46)31 (19–50)
    Year 118 (12–27)NS42 (26–77)NS
    Year 220 (11–28)46 (22–76)
Pro-MMP-8 (U/ml)
    Baseline91 (54–121)93 (59–130)
    Year 178 (43–102)<0.00165 (45–111)<0.001
    Year 251 (23–108)65 (49–102)
Pro-MMP-9 (U/ml)
    Baseline54 (44–66)53 (42–74)
    Year 151 (34–57)<0.00150 (40–60)<0.001
    Year 239 (31–48)49 (30–59)
MMP/α2M (U/ml)
    Baseline4.2 (3.5–5.7)4.6 (3.6–7.4)
    Year 13.4 (2.7–4.6)<0.0014.0 (3.5–6.1)NS
    Year 23.4 (2.3–4.8)4.4 (3.7–5.5)